The Program's goal is to train pre-doctoral and postdoctoral biostatisticians in statistical theory and methods as applied to environmental health (EHS). This aim is addressed by an integrated collaboration between biostatisticians, environmental epidemiologists and toxicologists to provide: supervision by biostatisticians with extensive experience in the development of statistical methodology; interaction with researchers with extensive experience in human and animal studies; practical experience in the applications of statistical methodology to problems in toxicology by participating in consulting projects and attending colloquia; mentoring of trainees to assist in developing independent academic careers. Training: This Training Program is a collaboration between the Departments of Biostatistics and Computational Biology (DBCB), the Environmental Health Sciences Center and the Department of Public Health Sciences. The DBCB offers a Ph.D. degree in Statistics with an option in Biostatistics. The Department, created to foster biostatistical research and collaboration with researchers in the Medical Center, provides the administrative leadership and the critical link with the epidemiologists and toxicologists. Trainees will be matched with a biostatistician as primary preceptor and an environmental health scientist as a secondary cosponsor. The Environmental Health Sciences Biostatistics Training Grant Committee will review the progress of the trainees and the program. Trainees: Pre-doctoral trainees will have completed a baccalaureate degree with a major in mathematics, statistics, or a science major with a strong minor in mathematics or statistics. Selection is based on academic record, GRE scores, and recommendations. Pre-doctoral trainees must fulfill the standard requirements for the Ph.D. degree in statistics plus additional courses in biostatistics, epidemiology and toxicology. Three pre-doctoral awards will be granted, for up to four years. Postdoctoral trainees must have completed a Ph.D. in statistics, mathematics or a related discipline, or have basic science training with strong quantitative skills Each postdoctoral trainee will enroll in appropriate courses, attend seminars, and work with faculty mentors on biostatistics research and specific toxicology related projects. One postdoctoral traineeship will be supported in each year of the program.